Grinding wheel dresser



R. E. DAHL l GRINDING WHEEL DREssER oct. 14, 1947.`

Filed Npv.` 29, 1945 www? 50' j Patented Oct. 14, 1947 UNITED STATESPATENT OFFICE GRINDING WHEEL DRESSER Robert E. Dahl, Cicero, Ill.Application November 29, 1945, Serial No. 631,709

My invention relates to grinding wheel dressers, `and more particularlyto a device adapted to form abrasive wheels, such as grinding wheels, inany desired manner so they may be employed in performing precisiongrinding or finishing work.

There are abrasive wheel dressers in the prior art, but most of theseare complicated and eX- pensive.

One object of my invention is to provide a wheel dresser of simple,sturdy and efficient construction whereby accurate abrasive wheeldressing may be performed in an expeditious, convenient and simplemanner.

Another object of my invention is to provide a grinding wheel dresser ofsuch simplicity that it may be manufactured cheaply and thus supply antimportant tool to industry at a reasonable cos A further object of myinvention is to provide a novel grinding wheel dresser having stops tolimit the amplitude of motion of the tool during the dressing operation.

3 Claims. (Cl. 12S- 11) Other and further objects of my invention willappear from the following description.

In the accompanying drawings, which form part of the instantspecification and which are to be read in conjunction therewith and inwhich like reference numerals are used to indicate like parts in thevarious views:

Fig. 1 is a perspective View of a grinding wheel Jdresser showing oneembodiment of my invenion.

Fig. 2 is a side elevation of the dresser shown in Fig. 1 with parts insection.

Fig. 3 is a sectional view taken along the line 3 3 of Fig. 2.

Fig. 4 is a sectional view on an enlarged scale taken along the line 4 4of Fig. 2.

In general, my invention contemplates a suitable base of rigidconstruction adapted to be positioned adjacent the grinding or abrasivewheel to be dressed. Rotatably mounted on the base I provide a headcarrying an arm in which the diamond dressing tool is positioned. It isa feature of my invention that the arm extends beneath the grindingWheel. This (offers several advantages. First, the wheel is trimmed atthe bottom, which is the actual line of contact with the work with whichthe grinding'wheel is used. Secondly, it is not necessary to move thesafety guard from its position over the grinding wheel, thus expeditingthe operation and guarding the workman from possible injury. Thirdly,the table top on which the base is mounted is in a position closer tothe wheel, reducing vibrations and making for accuracy, which is soimportant in high precision grinding since the position of the nal workcan be no more accurate than that of the tool used to perform the work.

The rotatable head .is provided with calibrations to indicate the anglewith respect to the vertical .at which the tool is positioned. In orderto limit 'the amplitude of motion during the dressing operation, Iprovide adjustable stops which are a feature of the instant invention.These stops will give the desired amount of arc travel to the diamond.

More particularly, referring now 'to the drawings, a base of anysuitable construction is :formed by a bottom plate I carrying a verticalor supporting plate 2 which is secured to the base I by means of machinescrews 3. A hub I is secured to the vertical plate 2 by means of machinescrews 5 as can readily be seen by reference to Fig. 2. Rotatablycarried by the hub I provide a revolving head 6 which may be tted with ahead handle 1. A plurality of threaded openings 8 are positioned atspaced points around the head to receive the handle 'I. The lowerportion of the head is fitted with a slot into which a diamond holdingarm 9 is positioned by means of screw IIB. The screw Iii is annular inform and is internally threaded to receive a set screw I I. A buffermember I2 of soft metal is positioned between the end of set screw IIand the hub 4 to avoid marring the hub surface around which the head 6rotates. The hub 4 is provided with an internally threaded opening I3adapted to receive the threaded end I4 of a screw I5. The threads II areright handed. The head of the screw I5 .is provided with a threadedportion I6 which threads are left handed in direction. The head of thescrew I5 and the threaded portion I4 are joined by a body member havinga tapered portion I'I. A knurled clamping disk I8 is threaded on theleft handed thread I5. Positioned between the hub 4 and the clampingdisk I3 are two stcp plates I9 and 20 provided with stop arms 2I and 22,as can readily be seen by reference to Figs. 1 and 3. The center of stopplate 25J is provided with a beveled opening, the angularity of whichfrom the vertical is less than the inclined surface of the taperedportion I1 of the screw I5. For example, the surface of the opening instop plate 2i! may have a taper of say fty degrees, while the taperedportion of the screw will be inclined to an angle of sixty degrees fromthe vertical. In this manner, the

screwing of the screw I5 in a clockwise direction through the use of ascrew driver in the slot 23 will hold stop plate 2U in its adjustedposition. The stop plate I9 is disposed around a cylindrical portion 24of the screw I5. The turning Vof the clamping disk I8 in acounter-clockwise direction will clamp both plates I9 and 20 between theclamping disk I8 and the hub 4. Due to the fact that the screw threadsI6 extend in an opposite direction from the screw threads I4, theloosening of the clamping diskwill not disturb the setting of the stopplate 29 when it is desired to reset the stops for a different arc oftravel.

In operation, if it be desired to dress grinding wheel 25, the base I ispositioned adjacent the wheel and secured in any desired manner, as for`example by a magnetic surface plate, clamp, or the like. The parts willthen be in 'a position shown in Fig. 1. so as to permit the rotatablehead to rotate on the hub 4. The clamping disk I8 is loosenedr and thescrew I5 backed 01T to loosen the stop plate 20. r'Ihe stop plate 2U isset so that the arm 22 is in a position giving the desired limit ofmotion. The screw I5 is then screwed inwardly to hold the plate 2 in itsposition. V'Ihe stop plate I9 is then adjusted so that its arm 2I is inthe desired position of amplitude of motion of the-arm 9. The clampingdisk I8 is then rotated in a counter-clockwise direction so as t0 clampplates I9 and 29 between it and the hub 4. Let us assume that thesurface which is to be formed in the grinding wheel isto be convex. Insuch case, the diamond holder 26 having a diamond point 21 is positionedso that the point 21 is below the axis of the hub 4, and the tool holder26 is clamped in position by means of screw 28.

The grinding wheel 25 is rotated and the arm i 9 is swung through itsarc of motion by means of the handle 'I.

It will be seen that Ihave accomplished the objects of my invention. Bymeans of my stop members I may giveA a grinding wheel a plurality ofcurvatures, each having a different radius. I have provided a simple,accurate, inexpensive abrasive wheel dressing tool in which the dress-The set screw II is loosened 1. A dresser for abrasive Wheels, includingin combination a base, a hub carried by said base,

a. head rotatably carried by said hub, an arm positioned on said headbelow its axis of rotation, and means for limiting the amplitude ofrotation of said head between predetermined limits, said means forlimiting the amplitude of rotation of said head comprising a pair ofstop members and means for clamping said stop members to said hub. Y

2. A dresser for abrasive wheels, including in l combination a base, ahub carried by said base,

a head rotatably carried by said hub, an arm positioned on said headbelow its axis of rotation,

and means for limiting the amplitude of rotation of said head betweenpredetermined limits, said means for limiting the amplitude of rotationof said head including a pair of stoppmembers, means for clamping saidstop members-to said hub, including a screw having oppositely threadedportions formed thereon, saidfhub being yformed Awith an axiallyextending internally ing may be performed in an expeditious, coni ltails within the scope of the claims without departing from the spiritof the invention. It is, therefore, to be understood that this inventionis not to be limited to the specific `details shown and described.

Having thus described my invention. what I claim is;

threaded re-entrant portion, the end of said 'screw being positioned insaid threaded re-entrant portion, and a clamping member threadedlypositioned on the other threaded portion oi 3. A dresser for abrasiveWheels, including in combination a base, a hub carried by said base, ahead rotatably carried by said hub, an arm positioned on said head belowits axis of rotation, and means for limiting the amplitude of rotation`of said head between Vpredetermined limitssaid means for limiting theamplitude ofrotation of said head including aV pair of `stop members,means for clamping said stop members to said v hub, including a screwhaving oppositely threaded portions formed thereon, said hub beingformed with an axially extending internally threaded re-erltrantportion, the end of said screw being positioned in said threadedvre-entrant portion, a clamping member threadedly positioned on theotherthreaded portion of, said screw, said screw being formed with acylindrical portion and afrusto-conical portion intermediatesaidoppositely threaded portions, one of said stop members being positionedadjacent said frusto-conical portion, and the other of said stop membersbeing positioned ,adjacent said cylindrical portion.

Y ROBERT E. DAHL.

REFERENCES YCITED` The following-references are of record inthe le ofthis patent:Y f

UNITED STATES PATENTS Number Name Date 2,301,610 ABrady Nov. 10, 19422,178,135 Brady Oct. 31, 1939

